Weakly Solvating Electrolytes for Lithium and Post‐Lithium Rechargeable Batteries: Progress and Outlook

In the rapidly evolving global landscape of renewable energy sources, there is an increasing demand for high‐energy‐density rechargeable batteries essential for energy storage. Simultaneously, there is a growing emphasis on developing high‐stability electrolytes. The concepts of high concentration electrolytes (HCEs) and localized high concentration electrolytes (LHCEs) have emerged, with notable progress achieved by altering cation‐solvent and cation–anion solvation coordination environments. However, challenges persist, including high costs and low ionic conductivity. A recent development is the introduction of the weakly solvating electrolyte (WSE), which offers a new perspective on the design of stable electrolytes at conventional or low concentrations. This approach enables high‐performance rechargeable batteries by modulating the coordination structure of electrolytes to generate a unique anion‐driven interphase reaction chemistry. This review outlines the design principles of WSEs and their operating mechanisms when applied to rechargeable lithium and post‐lithium batteries. An outlook is also presented on the future research directions of WSE, coupled with an analysis of the technological challenges.